Scalable spin-based quantum computing demands precise and stable control of a large number of gate-defined quantum dots while minimizing wiring complexity and thermal load. Control architectures based on sample-and-hold (SH) multiplexing techniques offer a promising solution by enabling sequential programming of several gate voltages using a limited number of input lines. However, the compatibility of such dynamic voltage refreshing with the stringent stability, noise, and speed requirements of quantum dot operation is an active subject of study. Here we experimentally demonstrate that a multiplexing cryo-CMOS circuit can reliably bias a silicon double quantum dot (DQD) at 0.5K. Exploiting the isolated regime, we show deterministic loading and isolation of four electrons and stable access to all five charge configurations from (4,0) to (0,4), despite the sequential voltage refreshing. We further demonstrate rapid voltage pulsing across an inter-dot transition, resolving single-electron tunneling events and stochastic switching at the (1,3)-(0,4) transition. These results confirm that SH-based multiplexed control is compatible with both static biasing and pulsing of isolated quantum dots, representing an important milestone toward scalable cryogenic control architectures for large-scale spin-qubit processors.
@article{arxiv.2604.11266,
title = {Multiplexed cryo-CMOS control of an isolated double quantum dot},
author = {Mathieu Darnas and Mathilde Ouvrier-Buffet and Antoine Faurie and Jean-Baptiste Casanova and Benoit Bertrand and Candice Thomas and Jean Charbonnier and Jean-Philippe Michel and Bruna Cardoso Paz and Yvain Thonnart and Franck Badets and Franck Balestro and Matias Urdampilleta and Tristan Meunier and Baptiste Jadot},
journal= {arXiv preprint arXiv:2604.11266},
year = {2026}
}